Audio-visual contents of data storage media, e.g. Digital Versatile Discs (DVD) for video applications, usually contain menu data for various applications, e.g. to enable a user to select specific content of the medium. The menu data are used for rendering the menu on a display screen. Often so-called multi-page menus are used, where each possible state of the menu is represented by a full-screen image that is overlaid as a separate layer to the video picture. The menu layer is usually transparent, except for the displayed menu items.
In state-of-the-art menus the menu items basically consist of a number of buttons and non-button objects. Each button is assigned an on-screen position by the content author and can be navigated and activated by the user, e.g. via a remote control. Each button is associated a state, which can either be the ‘normal’ (or ‘unselected’) state, the ‘selected’ state or the ‘activated’ state. Each button can provide a different visual representation in each state in order to give the user feedback.
However, these kinds of menus are rather static as there is no way to dynamically add or remove buttons from the screen, without re-rendering the whole screen. For content authors such more sophisticated menu features would be desirable, for example for the design of sub-menus. In such a case, additional buttons dynamically appear and disappear on the screen through user interaction.
The invention provides means to generate such dynamic menus.